This present application relates to an electronic device which functions, for example, as a field effect transistor, a light emitting element or a solar cell and a producing method for the electronic device.
Recently, development of electronic devices which use a thin film of organic molecules has been and is being proceeded energetically. Among such electronic devices, attention is paid to organic electronics devices (which may hereinafter referred to simply as organic devices) such as organic transistors, organic light emitting elements and organic solar cells. Final targets of such organic devices are directed to reduction in cost, reduction in weight, achievement of flexibility and achievement of high performances, and it is considered that the key to the development is the physical properties of the organic materials. The organic materials have such various advantages that
(1) a large-area organic device can be produced at a low cost through a simple and easy process at a low temperature; that
(2) it is possible to produce a flexible organic device; and that
(3) the performances or physical properties of an organic device can be controlled by modifying molecules of an organic material in a desired form.
However, some organic materials are liable to be oxidized, and when future placement into practical use is taken into consideration, organic materials are not satisfactory in terms of the chemical and physical stability. In this regard, it is considered that there is room for improvement in the organic materials. From such a point of view as just described, attention is paid recently to a hybrid material of organic and inorganic materials which has superior stability and physical properties of an inorganic semiconductor material and has applicability of a solution process provided by an organic semiconductor material.
From among such organic and inorganic hybrid materials as mentioned above, a composite material composed of mixture of semiconductor nano-grains and conjugate polymer is being investigated, and energetic investigations have been and are being made in various fields. As a result of such investigations, various proposals have been made. For example, a solar cell is disclosed in W. U. Huynh et al., Science 2002, 295, 2425, (hereinafter referred to as Non-Patent Document 1) or W. J. E. Beek et al., Adv. Func. Matter, 2005, 15, 1703 (hereinafter referred to as Non-Patent Document 2); a light emitting element is disclosed in V. L. Colvin et al., Nature 1994, 370, 354 (hereinafter referred to as Non-Patent Document 3), S. Coe et al., Nature 2002, 420, 800 (hereinafter referred to as Non-Patent Document 4), or A. H. Mueller et al., Nano Lett., 2005, 5, 1039 (hereinafter referred to as Non-Patent Document 5); and a field effect transistor is disclosed in D. Yu et al., Science 2003, 300, 1277 (hereinafter referred to as Non-Patent Document 6) or D. V. Talapin et al., Science 2005, 310, 86 (hereinafter referred to as Non-Patent Document 7).
However, where a composite material of mixture of semiconductor nano-grains and conjugate polymer is formed into a thin film, phase separation occurs between the semiconductor nano-grains and the conjugate polymer, for example, because of heat generated upon use of the organic device. Such phase separation makes a cause of deterioration of the performance of the organic device.